This invention relates to a rotor for a self-starting permanent magnet disk motor and more specifically to a rotor for a self-starting permanent magnet disk motor of the claw-pole or Lundell type.
Sychronous reluctance motors are presently being used in specialized processes that require accurate speed control and in processes where several motors are interconnted and have to be coordinated such as in continuous processing with tension control. Usually power is supplied to the synchronous reluctance motors by an adjustable frequency inverter. Synchronous reluctance motors have a poor power factor which decreases efficiency and increases the kVA rating and cost of the associated inverters.
AC permanent magnet motors are of the synchronous type and have excellent electrical characteristics. Typically, the efficiency of an AC permanent magnet motor will exceed that of a comparable induction motor and will greatly exceed that of a reluctance machine.
A self-starting permanent magnet motor is shown in U.S. Pat. No. 4,139,790 issued to Steen on Feb. 13, 1979. The motor has a laminated rotor with magnet segments inserted in apertures in the lamination and conducting bars inserted in slots in the lamination to form a squirrel cage winding. Laminated rotors are expensive to manufacture.
It is an object of the present invention to provide a low cost, self-starting permanent magnet rotor.